Is Duolingo running slow for anyone else?

Duolingo is running very slow for me today. It takes about 10-20 seconds for it to grade each answer in a lesson. I thought it was just my connection but everything else runs fine and I checked and my connection speed is 57mbps down and around 6mbps up. So that's not it.

update

It's running a bit faster now, at around 5 seconds per "grading". Still pretty slow compared to usual though.

This is pure speculation, but for me the slowness of the site seems to correlate well with how many people are likely online in the US. I'd say it's reasonable to assume that this is just high load on the servers, which I'm sure Duolingo is aware of. Given the explosive growth in popularity of the site, I'm very impressed that they have kept their servers from melting completely. That said, there are annoying bugs that show up when things are slow (I often get sent back to the home page upon completing a lesson, for example).